Generally, it has been recognized that vigorous activities such as sports and exercising result in the loss of salt and other minerals through sweating. The production of eccrine transpiration is the physiological mechanism to eliminate excess heat from the human body by fluid evaporation on the skin. According to environmental conditions and physical exercise, daily fluid losses of up to 3 liters may occur. In such conditions, one tends to compensate these fluid losses, through a physiological thirst mechanism, by the intake of sufficient fluid.
It has been established that along with eccrine transpiration, significant amounts of electrolytes are eliminated, which may account for systemic losses of up to 75 mEq of Na+ and Cl−, 60 mEq of K+ and Ca++, and 10 mEq of HCO3− (Seutter et al., The Quantitative Analysis of Some Constituents of Crude Sweat, Dermatolgica 141:226–233, 1970; Cage et al., Eccrine Glands in Dermatology in General Medicine, Fitzpatrick et al., McGraw-Hill, pp. 691–704, 1987). That such electrolyte losses may have negative consequences for the normal function of the human body has since long been recognized. The electrolyte losses consequent to excessive sweating, for instance in athletes, may contribute to early exhaustion, fatigue, muscle cramps, cardiac effects (arrhythmias) and CNS effects (asthenia). For this reason rational compositions have been successfully developed to reintegrate electrolyte losses by means of suitable rehydration beverages.
As far as reintegration of electrolyte losses in sportsmen is concerned, many compositions, particularly beverages are known which both rehydrate and provide energy to combat fatigue and stress. These compositions are specifically intended for people engaging in physical exercise, to improve performance and endurance. by supplying various sources of carbohydrates, along with selected mineral electrolytes.
For example, U.S. Pat. No. 5,292,538 (Paul et al.) describes a nutritional anabolic composition capable of providing for sustained energy as needed for strenuous physical exertion causing fatigue. This composition is essentially an energy formula in which carbohydrates play the foremost role. The characteristic feature of this composition lies in the particular combination of carbohydrate sources with partially hydrolyzed protein and magnesium in the form of an amino acid chelate. Additional electrolytes and vitamins play a subordinate role in achieving the objective of providing sustained energy and anabolic nutrition.
Like the above document, U.S. Pat. No. 5,270.297 (Paul et al.) describes a nutritional anabolic composition capable of providing for sustained energy as needed for strenuous physical exertion causing fatigue, with the additional objective of maintaining and/or enhancing the hydration state, besides the endurance, in conditions of physical stress, which is referred to physical exercise. The compositions claimed are centered on carbohydrate sources, and include amino acid chelates of sodium, calcium, potassium and manganese. It is to be noted that sodium levels of this composition are very high, like any other rehydration and energy formula for use in sports which the Inventors are aware of.
U.S. Pat. Nos. 5,032,411 and 5,114,723 (Stray-Gundersen) describe hypotonic beverage compositions intended for the intake by people engaging in physical activity, particularly in the heat, who have an increased metabolic demand and are in need of rehydration. The characteristic feature of these composition lies in the accurate definition of the osmolarity level to promote rapid absorption of the carbohydrate sources supplied in the beverage. The essential aspect of the compositions lies in the particular combination of carbohydrate sources with iron and other electrolytes.
U.S. Pat. No. 5,294,606 (Hastings) is directed to an isotonic energy composition, based on various carbohydrates along with the mineral electrolytes used for rehydration of sportsmen. The composition also contains chromium. U.S. Pat. No. 4,322,407 (Ko) describes an electrolyte drink intended for physical recovery after strenuous exercise. It supplies a high level of carbohydrate energy sources, along with mineral electrolytes used for rehydration of sportsmen and vitamin C. U.S. Pat. No. 4,874,606 (Boyle et al.) refers to a rapidly hydrating beverage for use by people engaging in medium to heavy levels of exercise. This beverage essentially supplies carbohydrate, sodium chloride, citrate and a specific compound (L-aspartyl-L-phenyl-alanine methyl ester) claimed to increase the rate of gastric emptying. It does not supply other electrolytes, oligoelements or vitamins. U.S. Pat. No. 4,309,417 (Staples) describes a beverage composition intended for the rapid replacement of body fluids, proteins and electrolytes lost during periods of strenuous physical activity. This composition is essentially directed to the use of whey protein concentrate as an energy source, besides the usual carbohydrates. It contains a high level of sodium, needed to achieve isotonicity of the solution, and the oligoelements naturally deriving from the whey protein. U.S. Pat. No. 3,894,148 (Ecker) is directed to a method for enhancing the energy metabolism of sportsmen, by administering fructose, used in conjunction with an electrolyte mix of sodium and potassium ions, as chlorides and as phosphates. The objective is to avoid the oxygen debt, causing build-up of lactic acid in athletes' muscles. U.S. Pat. No. 4,042,684 (Kahm) describes a dietetic beverage intended to supply carbohydrate and electrolytes to subjects engaging in vigorous physical activity, including hot and/or humid environments. The beverage only supplies, along with the sugars, sodium and potassium electrolytes. U.S. Pat. No. 4,448,770 (Epting) refers to a dietetic beverage for consumption by people needing fluid and electrolyte replacement during periods of exercise or potassium deficiency. This includes athletes and other people in conditions where fluid and/or potassium loss is a result of strenuous physical or mental activity, illness or side-effects of drugs. The beverage is essentially free of sodium ions, but supplies, besides sugar, very high levels of potassium, calcium and magnesium. U.S. Pat. No. 4,981,687 (Fregly et al.) describes a method and composition to improve physiological responses to exercise and exposure to sunlight and heat. The method to combat these effects is based on the administration of glycerol or pyruvate, besides the usual carbohydrate sources. It is to be noted that the beneficial action is based on a fluid retention effect. Subsequent patents released to the same authors (U.S. Pat. Nos. 5,147,650 and 5,236,712) extend such compositions to include lactate and alanine.
Beside rehydrating beverages or compositions for use in connection with physical exercise, often under strenuous conditions, other compositions are known from the prior art which pursue medical or pharmaceutical objectives.
For example, U.S. Pat. No. 5,626,884 (Lockett) describes a maintenance formula for patients suffering sickle cell disease, a genetically determined pathological modification of blood oxygenation. This document teaches a method of treating the above disease state of red blood cells by administering a very extensive cocktail of commonly known nutritional compounds. It is particularly important to note that this composition does not include sodium ions, which may be possibly present only in traces.
Other examples of medical compositions or processes for the preparation thereof include U.S. Pat. No. 4,725,427 (Ashmead et al.) which describes a technological process for the preparation of effervescent mineral granules, to be dissolved in water to yield a carbonated drink, supplying different ranges of vitamins and minerals in the form of amino chelates. The objective of this preparation is to improve the bioavailability of multivitamin mineral supplements in general, without any specific intended purpose. Further, U.S. Pat. No. 4,738,856 (Clark) describes a method to yield a beverage formulation intended for nutritional calcium supplementation, along with magnesium and potassium, in the form of readily absorbed organic salts. This beverage composition is intended to lower blood pressure, reduce blood alcohol, as well as supplying the recommended daily allowance of calcium, especially for post-menopausal women. U.S. Pat. No. 5,587,179 (Gergely et al.) is directed to a process for the manufacture of pharmaceutical formulations as effervescent or disintegrating tablets, with exemplifying reference to the administration of loperamide for the treatment of diarrhea. The mineral salts included have the significance of providing for the effervescent effect, combined with the compensation of electrolyte losses at the intestinal level. U.S. Pat. No. 5,536,506 (Majeed et al.) refers to the use of a natural alkaloid (piperine, in therapeutically effective amounts) to increase the gastrointestinal absorption, bioavailability and/or the metabolic utilization of diverse nutritional compounds, including many vegetal compounds, most vitamins, amino acids, and minerals. Also topical and intravenous administration is disclosed.
The Inventors have been involved in the problem that such beverages, widely used today for rehydration purposes in sportsmen, not to mention those pharmaceutical compositions specifically directed to treat specific diseases, appeared to be inappropriate for the support of transpiration problems in people undergoing thermal therapy such as hot mud applications.
Thermal treatment is widely used in Europe mainly for various types of musculoskeletal pathologies, which are reported to benefit significantly from the application of external heat. During a typical treatment session with thermal mud application, patients may lose up to two liters of transpiration, and consequently suffer avid thirst during and after the treatment sessions.
It is well known to the medical supervisors that these treatment consequences need accurate monitoring and adequate prevention, since if left untreated, severe sequelae may follow, in terms of the feared “thermal crisis”, associated with significant electrolyte imbalance, impairing cell function and causing systemic adverse effects, pathophysiologically similar to heat shock. In more general terms, thermal therapy induces a high level of “heat stress”.
The inventors found that the thermal therapy establishments determined that the rehydration beverages developed for sports purposes were not fit for their patients. First of all, these drinks generally contain a significant energy source, mostly in the form of readily absorbed and metabolized carbohydrates such as glucose. The great majority of patients undergoing thermal therapy are typically on a diet, because weight loss is a secondary benefit pursued by most patients applying for thermal therapy. Furthermore there is a high incidence of type II diabetes among these patients, most being elderly.
Apart from this obvious preoccupation on the carbohydrate component, the Inventors surmised that there could be significant physiological differences between the rehydration needs of young sportsmen and those of middle-aged and elderly people passively undergoing therapeutic heat application. It had indeed been reported by Fukumoto et al. in Differences in Composition of Sweat Induced by Thermal Exposure and by Running Exercise, Clinical Cardiology 11:707–709, (1988) that the composition of sweat differed significantly between volunteers when engaged in strenuous physical activity, and the same volunteers when submitting passively to environmental heat. They reported that during the passive heat conditions much lower amounts of sodium and chloride ions were found in the collected sweat samples than in the physical exercise conditions, whereas the levels of potassium ions were found to be comparable in both conditions.
On this basis, an investigation was made of the specific rehydration needs in passive heat conditions, such as applied during thermal therapy, in order to devise a physiologically appropriate nutritional support useful to reintegrate electrolyte losses in these conditions and to give suitable support for skin physiology. It had indeed been noted incidentally that patients' skin often appeared to suffer after repeated application of external heat, by means of thermal mud baths, showing signs of accelerated ageing, especially when associated with massive sunlight of UV exposure, often practiced in the Italian health spas.
More in general, there is thus a need for a composition suited for a person who sweats under conditions not associated with strenuous activities, such as passive heating or hyphen sweating, to compensate for the specific chemical imbalance arising from the sweating and further preferably to compensate for the biochemical changes which might occur in the person's skin. Such a composition preferably should be suited to be taken either before or after sweating.
The Inventors also found that rehydration needs of the patients subjected to thermal therapies are comparable to those of healthy people normally subjected to prolonged exposure to environmental heat and sunshine, especially in the absence of strenuous physical activity. Contrary to common beliefs, it has been found that the rehydration beverages developed for sports purposes are not fit for people in the above conditions. On the other side, it is simply not possible to think of providing a pharmaceutical composition to healthy people not subjected to medical supervision. A further problem which lies with providing healthy people with the majority of beverages of the known art is that assumption of carbohydrate components or sugar is contrary to the idea of getting or keeping a slim line, which is instead the aim of many.
It is therefore an object of the present invention to provide a composition for rehydration and restoration of electrolyte balance, which may prove useful in avoiding or ameliorating the adverse physiological effects which can result from prolonged exposure to environmental heath and sunshine, specifically in the absence of strenuous physical activity.
It is another object of the present invention to provide a composition of the type mentioned above which includes a correct amount of electrolytes to combat passive exposure to heat resulting in excessive transpiration/perspiration, without however providing a, high level of calories.
It is a further object of the present invention to provide a composition which is adapted to be provided in the form of a beverage, powder, solid items such as tablets and the like, and even in a frozen state.